It’s been a big week for the gene therapy universe. Of course, there’s the latest Barron’s cover story, which details the emerging medical revolution and highlights three stocks -- AveXis (AVXS), Regenxbio (RGNX), and Spark Therapeutics (ONCE) -- that have big stakes in what is widely considered one of the most exciting areas in the biotechnology arena. Last week, Ultragenyx Pharmaceutical (RARE) offered to buy Dimension Therapeutics (DMTX) for at $5.50 per share in cash.